/Engine/Source/Developer/SkeletalMeshUtilitiesCommon/Public/LODUtilities.h
This function apply the skinning weights from asource skeletal mesh to the destination skeletal mesh. The Destination will receive the weights has the alternate weights. We extract the imported skinning weight data from the SkeletalMeshSrc and we save the imported raw data into the destination mesh. Then we call UpdateAlternateSkinWeights without the SkeletalMeshSrc
static bool UpdateAlternateSkinWeights ( [USkeletalMesh](API\Runtime\Engine\Engine\USkeletalMesh) * SkeletalMeshDest, const [FName](API\Runtime\Core\UObject\FName) & ProfileNameDest, [USkeletalMesh](API\Runtime\Engine\Engine\USkeletalMesh) * SkeletalMeshSrc, int32 LODIndexDest, int32 LODIndexSrc, const [IMeshUtilities::MeshBuildOptions](API\Developer\MeshUtilities\IMeshUtilities\MeshBuildOptions) & Options )